The exemplary embodiment relates to object recognition and finds particular application in connection with a system and method for identification of an identifier of a vehicle while maintaining privacy of personal data.
Vehicle identification can be defined as the process of measuring a set of properties of a vehicle with one or multiple sensors and mapping it to a unique identifier. Visual sensors (e.g., cameras) are often used to capture an image containing a license plate and then an Automatic License Plate Recognition (ALPR) process is applied. Given an image containing a vehicle license plate, ALPR systems typically output the license plate number of the vehicle, which constitutes a unique identifier. The recognized identifier can be used for different purposes, such as automatic collection of tolls, enforcement, such as detection of speed violations, management of car parks, data mining for analysis of traffic patterns, and the like.
However, automatic vehicle identification poses some concerns for privacy rights, since the acquirer of the vehicle identifier, such as a car park owner, possesses data that can often be traced to the vehicle owner. There is also a risk that unauthorized persons may be able to access the data and use it for purposes other than the legitimate purposes for which it was collected.
In some countries, therefore, governments and citizens are becoming more concerned about the collection of such data and restrictions are being placed on its collection. The storage of a vehicle identifier in persistent memory has been recognized as a violation of the right to privacy in some European countries. To address this, number plate recognition system have been developed that place each passing vehicle identifier in temporary storage and access it directly in real-time to check for exceptional situations (such as a vehicle exceeding a speed limit). If there is no match, the data is not permanently stored.
Even where there is no government regulation, there is pressure to modify the process of automatic vehicle identification in car parks and other locations, including processing and storage of the identities, in order to preserve the privacy of the car park users.
U.S. patent application Ser. No. 14/054,998, filed Oct. 16, 2013, entitled DELAYED VEHICLE IDENTIFICATION FOR PRIVACY ENFORCEMENT, by Jose-Antonio Rodriguez Serrano, et al., the disclosure of which is incorporated herein by reference in its entirety, discloses a method for matching two license plate regions of two images without requiring recognizing the identity, e.g. the plate number, of the vehicles. The method preserves user privacy to comply with privacy requirements, since ALPR is performed only if some condition is met.
However, some regulations may require that the service operator provides proof that both the timestamp and the image at both locations are valid. This may raise concerns that recording time-stamped images taken at known locations may violate the protection of drivers' privacy, in view of other regulations.
There remains a need for a system and method which provides for the recognition of a unique identifier of an object, such as a vehicle, when a condition is met, and for providing proof of the validity of the underlying evidence used to determine that the condition is met, while at the same time, preserving the privacy of persons associated with the identifier.